LUCENE-7754: Inner classes should be static whenever possible.

lucene/CHANGES.txt

@@ -81,7 +81,11 @@ Other
 * LUCENE-7681: MemoryIndex uses new DocValues API (Alan Woodward)
 
 ======================= Lucene 6.6.0 =======================
-(No Changes)
+
+Other
+
+* LUCENE-7754: Inner classes should be static whenever possible.
+  (Daniel Jelinski via Adrien Grand)
 
 ======================= Lucene 6.5.0 =======================
 

lucene/analysis/common/src/java/org/apache/lucene/analysis/charfilter/HTMLStripCharFilter.java

@@ -30021,7 +30021,7 @@ public final class HTMLStripCharFilter extends BaseCharFilter {
     return ZZ_BUFFERSIZE;
   }
 
-  private class TextSegment extends OpenStringBuilder {
+  private static class TextSegment extends OpenStringBuilder {
     /** The position from which the next char will be read. */
     int pos = 0;
 

lucene/analysis/common/src/java/org/apache/lucene/analysis/charfilter/HTMLStripCharFilter.jflex

@@ -19,13 +19,12 @@ package org.apache.lucene.analysis.charfilter;
 
 import java.io.IOException;
 import java.io.Reader;
-import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
 
-import org.apache.lucene.analysis.util.CharArrayMap;
+import org.apache.lucene.analysis.CharArrayMap;
-import org.apache.lucene.analysis.util.CharArraySet;
+import org.apache.lucene.analysis.CharArraySet;
 import org.apache.lucene.analysis.util.OpenStringBuilder;
 
 /**
@@ -238,7 +237,7 @@ InlineElment = ( [aAbBiIqQsSuU]                   |
     return ZZ_BUFFERSIZE;
   }
 
-  private class TextSegment extends OpenStringBuilder {
+  private static class TextSegment extends OpenStringBuilder {
     /** The position from which the next char will be read. */
     int pos = 0;
 

lucene/analysis/common/src/java/org/apache/lucene/analysis/shingle/ShingleFilter.java

@@ -583,7 +583,7 @@ public final class ShingleFilter extends TokenFilter {
     }
   }
     
-  private class InputWindowToken {
+  private static class InputWindowToken {
     final AttributeSource attSource;
     final CharTermAttribute termAtt;
     final OffsetAttribute offsetAtt;

lucene/analysis/common/src/test/org/apache/lucene/analysis/hunspell/TestDictionary.java

@@ -157,7 +157,7 @@ public class TestDictionary extends LuceneTestCase {
     tempDir.close();
   }
   
-  private class CloseCheckInputStream extends FilterInputStream {
+  private static class CloseCheckInputStream extends FilterInputStream {
     private boolean closed = false;
 
     public CloseCheckInputStream(InputStream delegate) {

lucene/analysis/common/src/test/org/apache/lucene/analysis/miscellaneous/TestWordDelimiterFilter.java

@@ -184,7 +184,7 @@ public class TestWordDelimiterFilter extends BaseTokenStreamTestCase {
   /*
    * Set a large position increment gap of 10 if the token is "largegap" or "/"
    */
-  private final class LargePosIncTokenFilter extends TokenFilter {
+  private static final class LargePosIncTokenFilter extends TokenFilter {
     private CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
     private PositionIncrementAttribute posIncAtt = addAttribute(PositionIncrementAttribute.class);
     

lucene/analysis/common/src/test/org/apache/lucene/analysis/miscellaneous/TestWordDelimiterGraphFilter.java

@@ -171,7 +171,7 @@ public class TestWordDelimiterGraphFilter extends BaseTokenStreamTestCase {
   /*
    * Set a large position increment gap of 10 if the token is "largegap" or "/"
    */
-  private final class LargePosIncTokenFilter extends TokenFilter {
+  private static final class LargePosIncTokenFilter extends TokenFilter {
     private CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
     private PositionIncrementAttribute posIncAtt = addAttribute(PositionIncrementAttribute.class);
     

lucene/analysis/common/src/test/org/apache/lucene/analysis/payloads/NumericPayloadTokenFilterTest.java

@@ -57,7 +57,7 @@ public class NumericPayloadTokenFilterTest extends BaseTokenStreamTestCase {
     assertTrue(seenDogs + " does not equal: " + true, seenDogs == true);
   }
 
-  private final class WordTokenFilter extends TokenFilter {
+  private static final class WordTokenFilter extends TokenFilter {
     private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
     private final TypeAttribute typeAtt = addAttribute(TypeAttribute.class);
     

lucene/analysis/common/src/test/org/apache/lucene/analysis/payloads/TypeAsPayloadTokenFilterTest.java

@@ -47,7 +47,7 @@ public class TypeAsPayloadTokenFilterTest extends BaseTokenStreamTestCase {
     assertTrue(count + " does not equal: " + 10, count == 10);
   }
 
-  private final class WordTokenFilter extends TokenFilter {
+  private static final class WordTokenFilter extends TokenFilter {
     private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
     private final TypeAttribute typeAtt = addAttribute(TypeAttribute.class);
     

lucene/analysis/common/src/test/org/apache/lucene/analysis/sinks/TestTeeSinkTokenFilter.java

@@ -223,7 +223,7 @@ public class TestTeeSinkTokenFilter extends BaseTokenStreamTestCase {
   }
 
 
-  class ModuloTokenFilter extends TokenFilter {
+  static class ModuloTokenFilter extends TokenFilter {
 
     int modCount;
 
@@ -248,7 +248,7 @@ public class TestTeeSinkTokenFilter extends BaseTokenStreamTestCase {
     }
   }
 
-  class ModuloSinkFilter extends FilteringTokenFilter {
+  static class ModuloSinkFilter extends FilteringTokenFilter {
     int count = 0;
     int modCount;
 

lucene/analysis/common/src/test/org/apache/lucene/analysis/snowball/TestSnowball.java

@@ -71,7 +71,7 @@ public class TestSnowball extends BaseTokenStreamTestCase {
     assertEquals(new BytesRef(new byte[]{0,1,2,3}), payloadAtt.getPayload());
   }
   
-  private final class TestTokenStream extends TokenStream {
+  private static final class TestTokenStream extends TokenStream {
     private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
     private final OffsetAttribute offsetAtt = addAttribute(OffsetAttribute.class);
     private final TypeAttribute typeAtt = addAttribute(TypeAttribute.class);

lucene/analysis/common/src/test/org/apache/lucene/analysis/standard/TestUAX29URLEmailTokenizer.java

@@ -127,7 +127,7 @@ public class TestUAX29URLEmailTokenizer extends BaseTokenStreamTestCase {
   }
 
   /** Passes through tokens with type "<URL>" and blocks all other types. */
-  private class URLFilter extends TokenFilter {
+  private static class URLFilter extends TokenFilter {
     private final TypeAttribute typeAtt = addAttribute(TypeAttribute.class);
     public URLFilter(TokenStream in) {
       super(in);
@@ -146,7 +146,7 @@ public class TestUAX29URLEmailTokenizer extends BaseTokenStreamTestCase {
   }
   
   /** Passes through tokens with type "<EMAIL>" and blocks all other types. */
-  private class EmailFilter extends TokenFilter {
+  private static class EmailFilter extends TokenFilter {
     private final TypeAttribute typeAtt = addAttribute(TypeAttribute.class);
     public EmailFilter(TokenStream in) {
       super(in);

lucene/analysis/icu/src/java/org/apache/lucene/analysis/icu/ICUTransformFilter.java

@@ -112,7 +112,7 @@ public final class ICUTransformFilter extends TokenFilter {
   /**
    * Wrap a {@link CharTermAttribute} with the Replaceable API.
    */
-  final class ReplaceableTermAttribute implements Replaceable {
+  static final class ReplaceableTermAttribute implements Replaceable {
     private char buffer[];
     private int length;
     private CharTermAttribute token;

lucene/classification/src/test/org/apache/lucene/classification/CachingNaiveBayesClassifierTest.java

@@ -82,7 +82,7 @@ public class CachingNaiveBayesClassifierTest extends ClassificationTestBase<Byte
     }
   }
 
-  private class NGramAnalyzer extends Analyzer {
+  private static class NGramAnalyzer extends Analyzer {
     @Override
     protected TokenStreamComponents createComponents(String fieldName) {
       final Tokenizer tokenizer = new KeywordTokenizer();

lucene/classification/src/test/org/apache/lucene/classification/SimpleNaiveBayesClassifierTest.java

@@ -83,7 +83,7 @@ public class SimpleNaiveBayesClassifierTest extends ClassificationTestBase<Bytes
     }
   }
 
-  private class NGramAnalyzer extends Analyzer {
+  private static class NGramAnalyzer extends Analyzer {
     @Override
     protected TokenStreamComponents createComponents(String fieldName) {
       final Tokenizer tokenizer = new KeywordTokenizer();

lucene/codecs/src/java/org/apache/lucene/codecs/bloom/BloomFilteringPostingsFormat.java

@@ -218,7 +218,7 @@ public final class BloomFilteringPostingsFormat extends PostingsFormat {
       return delegateFieldsProducer.size();
     }
 
-    class BloomFilteredTerms extends Terms {
+    static class BloomFilteredTerms extends Terms {
       private Terms delegateTerms;
       private FuzzySet filter;
       
@@ -289,7 +289,7 @@ public final class BloomFilteringPostingsFormat extends PostingsFormat {
       }
     }
 
-    final class BloomFilteredTermsEnum extends TermsEnum {
+    static final class BloomFilteredTermsEnum extends TermsEnum {
       private Terms delegateTerms;
       private TermsEnum delegateTermsEnum;
       private final FuzzySet filter;

lucene/codecs/src/java/org/apache/lucene/codecs/memory/MemoryPostingsFormat.java

@@ -267,7 +267,7 @@ public final class MemoryPostingsFormat extends PostingsFormat {
   private static final int VERSION_START = 1;
   private static final int VERSION_CURRENT = VERSION_START;
 
-  private class MemoryFieldsConsumer extends FieldsConsumer {
+  private static class MemoryFieldsConsumer extends FieldsConsumer {
     private final SegmentWriteState state;
     private final IndexOutput out;
 

lucene/codecs/src/java/org/apache/lucene/codecs/simpletext/SimpleTextTermVectorsReader.java

@@ -239,7 +239,7 @@ public class SimpleTextTermVectorsReader extends TermVectorsReader {
     return scratchUTF16.toString();
   }
 
-  private class SimpleTVFields extends Fields {
+  private static class SimpleTVFields extends Fields {
     private final SortedMap<String,SimpleTVTerms> fields;
 
     SimpleTVFields(SortedMap<String,SimpleTVTerms> fields) {

lucene/core/src/java/org/apache/lucene/codecs/compressing/CompressingTermVectorsReader.java

@@ -742,7 +742,7 @@ public final class CompressingTermVectorsReader extends TermVectorsReader implem
 
   }
 
-  private class TVTerms extends Terms {
+  private static class TVTerms extends Terms {
 
     private final int numTerms, flags;
     private final int[] prefixLengths, suffixLengths, termFreqs, positionIndex, positions, startOffsets, lengths, payloadIndex;

lucene/core/src/java/org/apache/lucene/index/ParallelLeafReader.java

@@ -160,7 +160,7 @@ public class ParallelLeafReader extends LeafReader {
   }
 
   // Single instance of this, per ParallelReader instance
-  private final class ParallelFields extends Fields {
+  private static final class ParallelFields extends Fields {
     final Map<String,Terms> fields = new TreeMap<>();
     
     ParallelFields() {

lucene/core/src/java/org/apache/lucene/search/ConstantScoreQuery.java

@@ -68,7 +68,7 @@ public final class ConstantScoreQuery extends Query {
    *  wraps a query with its own optimized top-level
    *  scorer (e.g. BooleanScorer) we can use that
    *  top-level scorer. */
-  protected class ConstantBulkScorer extends BulkScorer {
+  protected static class ConstantBulkScorer extends BulkScorer {
     final BulkScorer bulkScorer;
     final Weight weight;
     final float theScore;

lucene/core/src/test/org/apache/lucene/index/TestCodecs.java

@@ -75,7 +75,7 @@ public class TestCodecs extends LuceneTestCase {
     NUM_TEST_ITER = atLeast(20);
   }
 
-  class FieldData implements Comparable<FieldData> {
+  static class FieldData implements Comparable<FieldData> {
     final FieldInfo fieldInfo;
     final TermData[] terms;
     final boolean omitTF;
@@ -107,7 +107,7 @@ public class TestCodecs extends LuceneTestCase {
     }
   }
 
-  class PositionData {
+  static class PositionData {
     int pos;
     BytesRef payload;
 
@@ -117,7 +117,7 @@ public class TestCodecs extends LuceneTestCase {
     }
   }
 
-  class TermData implements Comparable<TermData> {
+  static class TermData implements Comparable<TermData> {
     String text2;
     final BytesRef text;
     int[] docs;
@@ -300,7 +300,7 @@ public class TestCodecs extends LuceneTestCase {
     dir.close();
   }
 
-  private class Verify extends Thread {
+  private static class Verify extends Thread {
     final Fields termsDict;
     final FieldData[] fields;
     final SegmentInfo si;

lucene/core/src/test/org/apache/lucene/index/TestFlushByRamOrCountsPolicy.java

@@ -290,7 +290,7 @@ public class TestFlushByRamOrCountsPolicy extends LuceneTestCase {
     assertEquals(bytesUsed, flushControl.activeBytes());
   }
 
-  public class IndexThread extends Thread {
+  public static class IndexThread extends Thread {
     IndexWriter writer;
     LiveIndexWriterConfig iwc;
     LineFileDocs docs;

lucene/core/src/test/org/apache/lucene/index/TestIndexWriterExceptions.java

@@ -346,7 +346,7 @@ public class TestIndexWriterExceptions extends LuceneTestCase {
 
   private static String CRASH_FAIL_MESSAGE = "I'm experiencing problems";
 
-  private class CrashingFilter extends TokenFilter {
+  private static class CrashingFilter extends TokenFilter {
     String fieldName;
     int count;
 

lucene/core/src/test/org/apache/lucene/index/TestIndexWriterMerging.java

@@ -308,7 +308,7 @@ public class TestIndexWriterMerging extends LuceneTestCase {
   
   // Just intercepts all merges & verifies that we are never
   // merging a segment with >= 20 (maxMergeDocs) docs
-  private class MyMergeScheduler extends MergeScheduler {
+  private static class MyMergeScheduler extends MergeScheduler {
     @Override
     synchronized public void merge(IndexWriter writer, MergeTrigger trigger, boolean newMergesFound) throws IOException {
 

lucene/core/src/test/org/apache/lucene/index/TestIndexWriterWithThreads.java

@@ -51,7 +51,7 @@ import org.apache.lucene.util.LuceneTestCase.Slow;
 public class TestIndexWriterWithThreads extends LuceneTestCase {
 
   // Used by test cases below
-  private class IndexerThread extends Thread {
+  private static class IndexerThread extends Thread {
 
     boolean diskFull;
     Throwable error;

lucene/core/src/test/org/apache/lucene/index/TestIndexableField.java

@@ -41,7 +41,7 @@ import org.apache.lucene.util.TestUtil;
 
 public class TestIndexableField extends LuceneTestCase {
 
-  private class MyField implements IndexableField {
+  private static class MyField implements IndexableField {
 
     private final int counter;
     private final IndexableFieldType fieldType = new IndexableFieldType() {

lucene/core/src/test/org/apache/lucene/index/TestMaxTermFrequency.java

@@ -99,7 +99,7 @@ public class TestMaxTermFrequency extends LuceneTestCase {
   /**
    * Simple similarity that encodes maxTermFrequency directly as a byte
    */
-  class TestSimilarity extends TFIDFSimilarity {
+  static class TestSimilarity extends TFIDFSimilarity {
 
     @Override
     public float lengthNorm(FieldInvertState state) {

lucene/core/src/test/org/apache/lucene/index/TestNorms.java

@@ -50,7 +50,7 @@ import org.apache.lucene.util.TestUtil;
 public class TestNorms extends LuceneTestCase {
   final String byteTestField = "normsTestByte";
 
-  class CustomNormEncodingSimilarity extends TFIDFSimilarity {
+  static class CustomNormEncodingSimilarity extends TFIDFSimilarity {
 
     @Override
     public long encodeNormValue(float f) {

lucene/core/src/test/org/apache/lucene/index/TestPerSegmentDeletes.java

@@ -242,7 +242,7 @@ public class TestPerSegmentDeletes extends LuceneTestCase {
     return Arrays.copyOf(docs, numDocs);
   }
 
-  public class RangeMergePolicy extends MergePolicy {
+  public static class RangeMergePolicy extends MergePolicy {
     boolean doMerge = false;
     int start;
     int length;

lucene/core/src/test/org/apache/lucene/index/TestStressIndexing2.java

@@ -686,7 +686,7 @@ public class TestStressIndexing2 extends LuceneTestCase {
     assertFalse(fieldsEnum2.hasNext());
   }
 
-  private class IndexingThread extends Thread {
+  private static class IndexingThread extends Thread {
     IndexWriter w;
     int base;
     int range;

lucene/core/src/test/org/apache/lucene/index/TestTermVectorsReader.java

@@ -50,7 +50,7 @@ public class TestTermVectorsReader extends LuceneTestCase {
   private FieldInfos fieldInfos = new FieldInfos(new FieldInfo[0]);
   private static int TERM_FREQ = 3;
 
-  private class TestToken implements Comparable<TestToken> {
+  private static class TestToken implements Comparable<TestToken> {
     String text;
     int pos;
     int startOffset;

lucene/core/src/test/org/apache/lucene/index/TestTransactionRollback.java

@@ -157,7 +157,7 @@ public class TestTransactionRollback extends LuceneTestCase {
   }
 
   // Rolls back to previous commit point
-  class RollbackDeletionPolicy extends IndexDeletionPolicy {
+  static class RollbackDeletionPolicy extends IndexDeletionPolicy {
     private int rollbackPoint;
 
     public RollbackDeletionPolicy(int rollbackPoint) {
@@ -197,7 +197,7 @@ public class TestTransactionRollback extends LuceneTestCase {
     }
   }
 
-  class DeleteLastCommitPolicy extends IndexDeletionPolicy {
+  static class DeleteLastCommitPolicy extends IndexDeletionPolicy {
 
     @Override
     public void onCommit(List<? extends IndexCommit> commits) throws IOException {}
@@ -222,7 +222,7 @@ public class TestTransactionRollback extends LuceneTestCase {
   }
 
   // Keeps all commit points (used to build index)
-  class KeepAllDeletionPolicy extends IndexDeletionPolicy {
+  static class KeepAllDeletionPolicy extends IndexDeletionPolicy {
     @Override
     public void onCommit(List<? extends IndexCommit> commits) throws IOException {}
     @Override

lucene/core/src/test/org/apache/lucene/index/TestUniqueTermCount.java

@@ -98,7 +98,7 @@ public class TestUniqueTermCount extends LuceneTestCase {
   /**
    * Simple similarity that encodes maxTermFrequency directly
    */
-  class TestSimilarity extends Similarity {
+  static class TestSimilarity extends Similarity {
 
     @Override
     public long computeNorm(FieldInvertState state) {

lucene/core/src/test/org/apache/lucene/search/TestCustomSearcherSort.java

@@ -183,7 +183,7 @@ public class TestCustomSearcherSort extends LuceneTestCase {
     if (VERBOSE) System.out.println(message);
   }
   
-  public class CustomSearcher extends IndexSearcher {
+  public static class CustomSearcher extends IndexSearcher {
     private int switcher;
     
     public CustomSearcher(IndexReader r, int switcher) {
@@ -212,7 +212,7 @@ public class TestCustomSearcherSort extends LuceneTestCase {
     }
   }
   
-  private class RandomGen {
+  private static class RandomGen {
     RandomGen(Random random) {
       this.random = random;
       base.set(1980, 1, 1);

lucene/core/src/test/org/apache/lucene/search/TestEarlyTerminatingSortingCollector.java

@@ -201,7 +201,7 @@ public class TestEarlyTerminatingSortingCollector extends LuceneTestCase {
     }
   }
 
-  private class TestTerminatedEarlySimpleCollector extends SimpleCollector {
+  private static class TestTerminatedEarlySimpleCollector extends SimpleCollector {
     private boolean collectedSomething;
     public boolean collectedSomething() {
       return collectedSomething;
@@ -216,7 +216,7 @@ public class TestEarlyTerminatingSortingCollector extends LuceneTestCase {
     }
   }
 
-  private class TestEarlyTerminatingSortingcollectorQueryTimeout implements QueryTimeout {
+  private static class TestEarlyTerminatingSortingcollectorQueryTimeout implements QueryTimeout {
     final private boolean shouldExit;
     public TestEarlyTerminatingSortingcollectorQueryTimeout(boolean shouldExit) {
       this.shouldExit = shouldExit;

lucene/core/src/test/org/apache/lucene/search/TestPrefixRandom.java

@@ -75,7 +75,7 @@ public class TestPrefixRandom extends LuceneTestCase {
   }
   
   /** a stupid prefix query that just blasts thru the terms */
-  private class DumbPrefixQuery extends MultiTermQuery {
+  private static class DumbPrefixQuery extends MultiTermQuery {
     private final BytesRef prefix;
     
     DumbPrefixQuery(Term term) {
@@ -88,7 +88,7 @@ public class TestPrefixRandom extends LuceneTestCase {
       return new SimplePrefixTermsEnum(terms.iterator(), prefix);
     }
 
-    private class SimplePrefixTermsEnum extends FilteredTermsEnum {
+    private static class SimplePrefixTermsEnum extends FilteredTermsEnum {
       private final BytesRef prefix;
 
       private SimplePrefixTermsEnum(TermsEnum tenum, BytesRef prefix) {

lucene/core/src/test/org/apache/lucene/search/TestRegexpRandom2.java

@@ -102,7 +102,7 @@ public class TestRegexpRandom2 extends LuceneTestCase {
   }
   
   /** a stupid regexp query that just blasts thru the terms */
-  private class DumbRegexpQuery extends MultiTermQuery {
+  private static class DumbRegexpQuery extends MultiTermQuery {
     private final Automaton automaton;
     
     DumbRegexpQuery(Term term, int flags) {

lucene/core/src/test/org/apache/lucene/search/TestSimilarityProvider.java

@@ -90,7 +90,7 @@ public class TestSimilarityProvider extends LuceneTestCase {
     assertTrue(foodocs.scoreDocs[0].score < bardocs.scoreDocs[0].score);
   }
   
-  private class ExampleSimilarityProvider extends PerFieldSimilarityWrapper {
+  private static class ExampleSimilarityProvider extends PerFieldSimilarityWrapper {
     private Similarity sim1 = new Sim1();
     private Similarity sim2 = new Sim2();
     
@@ -104,7 +104,7 @@ public class TestSimilarityProvider extends LuceneTestCase {
     }
   }
   
-  private class Sim1 extends TFIDFSimilarity {
+  private static class Sim1 extends TFIDFSimilarity {
     
     @Override
     public long encodeNormValue(float f) {
@@ -142,7 +142,7 @@ public class TestSimilarityProvider extends LuceneTestCase {
     }
   }
   
-  private class Sim2 extends TFIDFSimilarity {
+  private static class Sim2 extends TFIDFSimilarity {
     
     @Override
     public long encodeNormValue(float f) {

lucene/core/src/test/org/apache/lucene/search/TestTermScorer.java

@@ -153,7 +153,7 @@ public class TestTermScorer extends LuceneTestCase {
     assertTrue("doc should be number 5", ts.docID() == 5);
   }
   
-  private class TestHit {
+  private static class TestHit {
     public int doc;
     public float score;
     

lucene/core/src/test/org/apache/lucene/search/TestTimeLimitingCollector.java

@@ -320,7 +320,7 @@ public class TestTimeLimitingCollector extends LuceneTestCase {
   }
   
   // counting collector that can slow down at collect().
-  private class MyHitCollector extends SimpleCollector {
+  private static class MyHitCollector extends SimpleCollector {
     private final BitSet bits = new BitSet();
     private int slowdown = 0;
     private int lastDocCollected = -1;

lucene/core/src/test/org/apache/lucene/store/TestLockFactory.java

@@ -76,7 +76,7 @@ public class TestLockFactory extends LuceneTestCase {
         }
     }
 
-    class MockLockFactory extends LockFactory {
+    static class MockLockFactory extends LockFactory {
 
         public Map<String,Lock> locksCreated = Collections.synchronizedMap(new HashMap<String,Lock>());
 
@@ -87,7 +87,7 @@ public class TestLockFactory extends LuceneTestCase {
             return lock;
         }
 
-        public class MockLock extends Lock {
+        public static class MockLock extends Lock {
 
             @Override
             public void close() {

lucene/core/src/test/org/apache/lucene/util/TestCloseableThreadLocal.java

@@ -40,7 +40,7 @@ public class TestCloseableThreadLocal extends LuceneTestCase {
     assertNull(ctl.get());
   }
 
-  public class InitValueThreadLocal extends CloseableThreadLocal<Object> {
+  public static class InitValueThreadLocal extends CloseableThreadLocal<Object> {
     @Override
     protected Object initialValue() {
       return TEST_VALUE;

lucene/core/src/test/org/apache/lucene/util/TestQueryBuilder.java

@@ -266,7 +266,7 @@ public class TestQueryBuilder extends LuceneTestCase {
     }
   }
   
-  private class SimpleCJKAnalyzer extends Analyzer {
+  private static class SimpleCJKAnalyzer extends Analyzer {
     @Override
     public TokenStreamComponents createComponents(String fieldName) {
       return new TokenStreamComponents(new SimpleCJKTokenizer());

lucene/core/src/test/org/apache/lucene/util/fst/TestFSTs.java

@@ -1458,7 +1458,7 @@ public class TestFSTs extends LuceneTestCase {
   }
 
   // used by slowcompletor
-  class TwoLongs {
+  static class TwoLongs {
     long a;
     long b;
 

lucene/facet/src/java/org/apache/lucene/facet/taxonomy/writercache/CollisionMap.java

@@ -185,7 +185,7 @@ public class CollisionMap {
     return memoryUsage;
   }
 
-  private class EntryIterator implements Iterator<Entry> {
+  private static class EntryIterator implements Iterator<Entry> {
     Entry next;    // next entry to return
     int index;        // current slot 
     Entry[] ents;

lucene/grouping/src/test/org/apache/lucene/search/grouping/GroupFacetCollectorTest.java

@@ -720,7 +720,7 @@ public class GroupFacetCollectorTest extends AbstractGroupingTestCase {
     return null;
   }
 
-  private class IndexContext {
+  private static class IndexContext {
 
     final int numDocs;
     final DirectoryReader indexReader;
@@ -744,7 +744,7 @@ public class GroupFacetCollectorTest extends AbstractGroupingTestCase {
     }
   }
 
-  private class GroupedFacetResult {
+  private static class GroupedFacetResult {
 
     final int totalCount;
     final int totalMissingCount;

lucene/highlighter/src/test/org/apache/lucene/search/uhighlight/visibility/TestUnifiedHighlighterExtensibility.java

@@ -202,7 +202,7 @@ public class TestUnifiedHighlighterExtensibility extends LuceneTestCase {
   }
 
   /** Tests maintaining extensibility/visibility of {@link org.apache.lucene.search.uhighlight.FieldHighlighter} out of package. */
-  private class CustomFieldHighlighter extends FieldHighlighter {
+  private static class CustomFieldHighlighter extends FieldHighlighter {
     CustomFieldHighlighter(String field, FieldOffsetStrategy fieldOffsetStrategy, BreakIterator breakIterator, PassageScorer passageScorer, int maxPassages, int maxNoHighlightPassages, PassageFormatter passageFormatter) {
       super(field, fieldOffsetStrategy, breakIterator, passageScorer, maxPassages, maxNoHighlightPassages, passageFormatter);
     }

lucene/queries/src/java/org/apache/lucene/queries/CustomScoreQuery.java

@@ -238,7 +238,7 @@ public class CustomScoreQuery extends Query implements Cloneable {
   /**
    * A scorer that applies a (callback) function on scores of the subQuery.
    */
-  private class CustomScorer extends FilterScorer {
+  private static class CustomScorer extends FilterScorer {
     private final float qWeight;
     private final Scorer subQueryScorer;
     private final Scorer[] valSrcScorers;

lucene/queries/src/test/org/apache/lucene/queries/TestCustomScoreQuery.java

@@ -153,7 +153,7 @@ public class TestCustomScoreQuery extends FunctionTestSetup {
     }
   }
 
-  private final class CustomExternalQuery extends CustomScoreQuery {
+  private static final class CustomExternalQuery extends CustomScoreQuery {
 
     @Override
     protected CustomScoreProvider getCustomScoreProvider(LeafReaderContext context) throws IOException {

lucene/queries/src/test/org/apache/lucene/queries/payloads/TestPayloadSpans.java

@@ -461,7 +461,7 @@ public class TestPayloadSpans extends LuceneTestCase {
     assertEquals("expected numSpans", numSpans, cnt);
   }
 
-  final class PayloadAnalyzer extends Analyzer {
+  static final class PayloadAnalyzer extends Analyzer {
 
     @Override
     public TokenStreamComponents createComponents(String fieldName) {
@@ -470,7 +470,7 @@ public class TestPayloadSpans extends LuceneTestCase {
     }
   }
 
-  final class PayloadFilter extends TokenFilter {
+  static final class PayloadFilter extends TokenFilter {
     Set<String> entities = new HashSet<>();
     Set<String> nopayload = new HashSet<>();
     int pos;
@@ -515,7 +515,7 @@ public class TestPayloadSpans extends LuceneTestCase {
     }
   }
   
-  public final class TestPayloadAnalyzer extends Analyzer {
+  public static final class TestPayloadAnalyzer extends Analyzer {
 
     @Override
     public TokenStreamComponents createComponents(String fieldName) {

lucene/queryparser/src/test/org/apache/lucene/queryparser/classic/TestMultiAnalyzer.java

@@ -120,7 +120,7 @@ public class TestMultiAnalyzer extends BaseTokenStreamTestCase {
    * Expands "multi" to "multi" and "multi2", both at the same position,
    * and expands "triplemulti" to "triplemulti", "multi3", and "multi2".
    */
-  private class MultiAnalyzer extends Analyzer {
+  private static class MultiAnalyzer extends Analyzer {
 
     @Override
     public TokenStreamComponents createComponents(String fieldName) {
@@ -129,7 +129,7 @@ public class TestMultiAnalyzer extends BaseTokenStreamTestCase {
     }
   }
 
-  private final class TestFilter extends TokenFilter {
+  private static final class TestFilter extends TokenFilter {
 
     private String prevType;
     private int prevStartOffset;
@@ -191,7 +191,7 @@ public class TestMultiAnalyzer extends BaseTokenStreamTestCase {
    * Analyzes "the quick brown" as: quick(incr=2) brown(incr=1).
    * Does not work correctly for input other than "the quick brown ...".
    */
-  private class PosIncrementAnalyzer extends Analyzer {
+  private static class PosIncrementAnalyzer extends Analyzer {
 
     @Override
     public TokenStreamComponents createComponents(String fieldName) {
@@ -200,7 +200,7 @@ public class TestMultiAnalyzer extends BaseTokenStreamTestCase {
     }
   }
 
-  private final class TestPosIncrementFilter extends TokenFilter {
+  private static final class TestPosIncrementFilter extends TokenFilter {
 
     CharTermAttribute termAtt;
     PositionIncrementAttribute posIncrAtt;

lucene/queryparser/src/test/org/apache/lucene/queryparser/classic/TestMultiFieldQueryParser.java

@@ -336,7 +336,7 @@ public class TestMultiFieldQueryParser extends LuceneTestCase {
   }
 
   /** whitespace+lowercase analyzer with synonyms (dogs,dog) and (guinea pig,cavy) */
-  private class MockSynonymAnalyzer extends Analyzer {
+  private static class MockSynonymAnalyzer extends Analyzer {
     @Override
     public TokenStreamComponents createComponents(String fieldName) {
       Tokenizer tokenizer = new MockTokenizer(MockTokenizer.WHITESPACE, true);

lucene/queryparser/src/test/org/apache/lucene/queryparser/flexible/standard/TestMultiAnalyzerQPHelper.java

@@ -139,7 +139,7 @@ public class TestMultiAnalyzerQPHelper extends LuceneTestCase {
    * Expands "multi" to "multi" and "multi2", both at the same position, and
    * expands "triplemulti" to "triplemulti", "multi3", and "multi2".
    */
-  private class MultiAnalyzer extends Analyzer {
+  private static class MultiAnalyzer extends Analyzer {
 
     @Override
     public TokenStreamComponents createComponents(String fieldName) {
@@ -148,7 +148,7 @@ public class TestMultiAnalyzerQPHelper extends LuceneTestCase {
     }
   }
 
-  private final class TestFilter extends TokenFilter {
+  private static final class TestFilter extends TokenFilter {
 
     private String prevType;
     private int prevStartOffset;
@@ -206,7 +206,7 @@ public class TestMultiAnalyzerQPHelper extends LuceneTestCase {
    * Analyzes "the quick brown" as: quick(incr=2) brown(incr=1). Does not work
    * correctly for input other than "the quick brown ...".
    */
-  private class PosIncrementAnalyzer extends Analyzer {
+  private static class PosIncrementAnalyzer extends Analyzer {
 
     @Override
     public TokenStreamComponents createComponents(String fieldName) {
@@ -215,7 +215,7 @@ public class TestMultiAnalyzerQPHelper extends LuceneTestCase {
     }
   }
 
-  private class TestPosIncrementFilter extends TokenFilter {
+  private static class TestPosIncrementFilter extends TokenFilter {
 
     private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
     private final PositionIncrementAttribute posIncrAtt = addAttribute(PositionIncrementAttribute.class);

lucene/queryparser/src/test/org/apache/lucene/queryparser/flexible/standard/TestQPHelper.java

@@ -350,7 +350,7 @@ public class TestQPHelper extends LuceneTestCase {
   }
 
   //individual CJK chars as terms, like StandardAnalyzer
-  private class SimpleCJKTokenizer extends Tokenizer {
+  private static class SimpleCJKTokenizer extends Tokenizer {
     private CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
 
     public SimpleCJKTokenizer() {
@@ -368,7 +368,7 @@ public class TestQPHelper extends LuceneTestCase {
     }
   }
 
-  private class SimpleCJKAnalyzer extends Analyzer {
+  private static class SimpleCJKAnalyzer extends Analyzer {
     @Override
     public TokenStreamComponents createComponents(String fieldName) {
       return new TokenStreamComponents(new SimpleCJKTokenizer());
@@ -1252,7 +1252,7 @@ public class TestQPHelper extends LuceneTestCase {
     super.tearDown();
   }
 
-  private class CannedTokenizer extends Tokenizer {
+  private static class CannedTokenizer extends Tokenizer {
     private int upto = 0;
     private final PositionIncrementAttribute posIncr = addAttribute(PositionIncrementAttribute.class);
     private final CharTermAttribute term = addAttribute(CharTermAttribute.class);
@@ -1291,7 +1291,7 @@ public class TestQPHelper extends LuceneTestCase {
     }
   }
 
-  private class CannedAnalyzer extends Analyzer {
+  private static class CannedAnalyzer extends Analyzer {
     @Override
     public TokenStreamComponents createComponents(String ignored) {
       return new TokenStreamComponents(new CannedTokenizer());

lucene/queryparser/src/test/org/apache/lucene/queryparser/util/QueryParserTestBase.java

@@ -264,7 +264,7 @@ public abstract class QueryParserTestBase extends LuceneTestCase {
     }
   }
 
-  private class SimpleCJKAnalyzer extends Analyzer {
+  private static class SimpleCJKAnalyzer extends Analyzer {
     @Override
     public TokenStreamComponents createComponents(String fieldName) {
       return new TokenStreamComponents(new SimpleCJKTokenizer());
@@ -1095,7 +1095,7 @@ public abstract class QueryParserTestBase extends LuceneTestCase {
   }
 
   /** whitespace+lowercase analyzer with synonyms */
-  protected class Analyzer1 extends Analyzer {
+  protected static class Analyzer1 extends Analyzer {
     public Analyzer1(){
       super();
     }
@@ -1107,7 +1107,7 @@ public abstract class QueryParserTestBase extends LuceneTestCase {
   }
   
   /** whitespace+lowercase analyzer without synonyms */
-  protected class Analyzer2 extends Analyzer {
+  protected static class Analyzer2 extends Analyzer {
     public Analyzer2(){
       super();
     }
@@ -1122,7 +1122,7 @@ public abstract class QueryParserTestBase extends LuceneTestCase {
   /**
    * Mock collation analyzer: indexes terms as "collated" + term
    */
-  private class MockCollationFilter extends TokenFilter {
+  private static class MockCollationFilter extends TokenFilter {
     private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
 
     protected MockCollationFilter(TokenStream input) {
@@ -1141,7 +1141,7 @@ public abstract class QueryParserTestBase extends LuceneTestCase {
     }
     
   }
-  private class MockCollationAnalyzer extends Analyzer {
+  private static class MockCollationAnalyzer extends Analyzer {
     @Override
     public TokenStreamComponents createComponents(String fieldName) {
       Tokenizer tokenizer = new MockTokenizer(MockTokenizer.WHITESPACE, true);

lucene/sandbox/src/java/org/apache/lucene/sandbox/queries/FuzzyLikeThisQuery.java

@@ -112,7 +112,7 @@ public class FuzzyLikeThisQuery extends Query
     this.maxNumTerms = maxNumTerms;
   }
 
-  class FieldVals
+  static class FieldVals
   {
     String queryString;
     String fieldName;

lucene/sandbox/src/test/org/apache/lucene/payloads/TestPayloadSpanUtil.java

@@ -72,7 +72,7 @@ public class TestPayloadSpanUtil extends LuceneTestCase {
     directory.close();
   }
 
-  final class PayloadAnalyzer extends Analyzer {
+  final static class PayloadAnalyzer extends Analyzer {
 
     @Override
     public TokenStreamComponents createComponents(String fieldName) {
@@ -81,7 +81,7 @@ public class TestPayloadSpanUtil extends LuceneTestCase {
     }
   }
 
-  final class PayloadFilter extends TokenFilter {
+  static final class PayloadFilter extends TokenFilter {
     Set<String> entities = new HashSet<>();
     Set<String> nopayload = new HashSet<>();
     int pos;

lucene/suggest/src/java/org/apache/lucene/search/spell/WordBreakSpellChecker.java

@@ -441,7 +441,7 @@ public class WordBreakSpellChecker {
     this.maxEvaluations = maxEvaluations;
   }
   
-  private class LengthThenMaxFreqComparator implements
+  private static class LengthThenMaxFreqComparator implements
       Comparator<SuggestWordArrayWrapper> {
     @Override
     public int compare(SuggestWordArrayWrapper o1, SuggestWordArrayWrapper o2) {
@@ -455,7 +455,7 @@ public class WordBreakSpellChecker {
     }
   }
   
-  private class LengthThenSumFreqComparator implements
+  private static class LengthThenSumFreqComparator implements
       Comparator<SuggestWordArrayWrapper> {
     @Override
     public int compare(SuggestWordArrayWrapper o1, SuggestWordArrayWrapper o2) {
@@ -469,7 +469,7 @@ public class WordBreakSpellChecker {
     }
   }
   
-  private class CombinationsThenFreqComparator implements
+  private static class CombinationsThenFreqComparator implements
       Comparator<CombineSuggestionWrapper> {
     @Override
     public int compare(CombineSuggestionWrapper o1, CombineSuggestionWrapper o2) {
@@ -484,7 +484,7 @@ public class WordBreakSpellChecker {
     }
   }
   
-  private class SuggestWordArrayWrapper {
+  private static class SuggestWordArrayWrapper {
     final SuggestWord[] suggestWords;
     final int freqMax;
     final int freqSum;
@@ -502,7 +502,7 @@ public class WordBreakSpellChecker {
     }
   }
   
-  private class CombineSuggestionWrapper {
+  private static class CombineSuggestionWrapper {
     final CombineSuggestion combineSuggestion;
     final int numCombinations;
     

lucene/suggest/src/java/org/apache/lucene/search/suggest/document/ContextQuery.java

@@ -238,7 +238,7 @@ public class ContextQuery extends CompletionQuery {
     }
   }
 
-  private class ContextCompletionWeight extends CompletionWeight {
+  private static class ContextCompletionWeight extends CompletionWeight {
 
     private final Map<IntsRef, Float> contextMap;
     private final int[] contextLengths;

lucene/suggest/src/java/org/apache/lucene/search/suggest/fst/ExternalRefSorter.java

@@ -105,7 +105,7 @@ public class ExternalRefSorter implements BytesRefSorter, Closeable {
    * Iterate over byte refs in a file.
    */
   // TODO: this class is a bit silly ... sole purpose is to "remove" Closeable from what #iterator returns:
-  class ByteSequenceIterator implements BytesRefIterator {
+  static class ByteSequenceIterator implements BytesRefIterator {
     private final OfflineSorter.ByteSequencesReader reader;
     private BytesRef scratch;
     

lucene/suggest/src/java/org/apache/lucene/search/suggest/fst/WFSTCompletionLookup.java

@@ -267,7 +267,7 @@ public class WFSTCompletionLookup extends Lookup implements Accountable {
     return Integer.MAX_VALUE - (int)value;
   }
   
-  private final class WFSTInputIterator extends SortedInputIterator {
+  private static final class WFSTInputIterator extends SortedInputIterator {
 
     WFSTInputIterator(Directory tempDir, String tempFileNamePrefix, InputIterator source) throws IOException {
       super(tempDir, tempFileNamePrefix, source);

lucene/suggest/src/java/org/apache/lucene/search/suggest/jaspell/JaspellLookup.java

@@ -147,17 +147,17 @@ public class JaspellLookup extends Lookup implements Accountable {
       node.data = Long.valueOf(in.readLong());
     }
     if ((mask & LO_KID) != 0) {
-      TSTNode kid = trie.new TSTNode('\0', node);
+      TSTNode kid = new TSTNode('\0', node);
       node.relatives[TSTNode.LOKID] = kid;
       readRecursively(in, kid);
     }
     if ((mask & EQ_KID) != 0) {
-      TSTNode kid = trie.new TSTNode('\0', node);
+      TSTNode kid = new TSTNode('\0', node);
       node.relatives[TSTNode.EQKID] = kid;
       readRecursively(in, kid);
     }
     if ((mask & HI_KID) != 0) {
-      TSTNode kid = trie.new TSTNode('\0', node);
+      TSTNode kid = new TSTNode('\0', node);
       node.relatives[TSTNode.HIKID] = kid;
       readRecursively(in, kid);
     }
@@ -196,7 +196,7 @@ public class JaspellLookup extends Lookup implements Accountable {
   @Override
   public boolean load(DataInput input) throws IOException {
     count = input.readVLong();
-    TSTNode root = trie.new TSTNode('\0', null);
+    TSTNode root = new TSTNode('\0', null);
     readRecursively(input, root);
     trie.setRoot(root);
     return true;

lucene/suggest/src/java/org/apache/lucene/search/suggest/jaspell/JaspellTernarySearchTrie.java

@@ -71,7 +71,7 @@ public class JaspellTernarySearchTrie implements Accountable {
   /**
    * An inner class of Ternary Search Trie that represents a node in the trie.
    */
-  protected final class TSTNode implements Accountable {
+  protected static final class TSTNode implements Accountable {
 
     /** Index values for accessing relatives array. */
     protected final static int PARENT = 0, LOKID = 1, EQKID = 2, HIKID = 3;

lucene/suggest/src/test/org/apache/lucene/search/suggest/DocumentDictionaryTest.java

@@ -411,7 +411,7 @@ public class DocumentDictionaryTest extends LuceneTestCase {
     return suggestionList;
   }
 
-  private class Suggestion {
+  private static class Suggestion {
     private long weight;
     private BytesRef payload;
     private Set<BytesRef> contexts;

lucene/suggest/src/test/org/apache/lucene/search/suggest/analyzing/AnalyzingInfixSuggesterTest.java

@@ -910,7 +910,7 @@ public class AnalyzingInfixSuggesterTest extends LuceneTestCase {
     a.close();
   }
 
-  private class IndexDocument implements Runnable {
+  private static class IndexDocument implements Runnable {
     AnalyzingInfixSuggester suggester;
     String key;
 

lucene/suggest/src/test/org/apache/lucene/search/suggest/analyzing/FuzzySuggesterTest.java

@@ -1118,7 +1118,7 @@ public class FuzzySuggesterTest extends LuceneTestCase {
 
   private static final Comparator<CharSequence> CHARSEQUENCE_COMPARATOR = new CharSequenceComparator();
 
-  public class CompareByCostThenAlpha implements Comparator<LookupResult> {
+  public static class CompareByCostThenAlpha implements Comparator<LookupResult> {
     @Override
     public int compare(LookupResult a, LookupResult b) {
       if (a.value > b.value) {

lucene/test-framework/src/java/org/apache/lucene/store/BaseLockFactoryTestCase.java

@@ -274,7 +274,7 @@ public abstract class BaseLockFactoryTestCase extends LuceneTestCase {
     }
   }
 
-  private class SearcherThread extends Thread { 
+  private static class SearcherThread extends Thread {
     private Directory dir;
     private int numIteration;
     public boolean hitException = false;

lucene/tools/src/java/org/apache/lucene/dependencies/GetMavenDependenciesTask.java

@@ -786,7 +786,7 @@ public class GetMavenDependenciesTask extends Task {
   /**
    * Stores information about an external dependency
    */
-  private class ExternalDependency implements Comparable<ExternalDependency> {
+  private static class ExternalDependency implements Comparable<ExternalDependency> {
     String groupId;
     String artifactId;
     boolean isTestDependency;

lucene/tools/src/java/org/apache/lucene/validation/LibVersionsCheckTask.java

@@ -150,7 +150,7 @@ public class LibVersionsCheckTask extends Task {
    */
   private Map<String,HashSet<String>> ignoreConflictVersions = new HashMap<>();
 
-  private class Dependency {
+  private static class Dependency {
     String org;
     String name;
     String directVersion;

solr/contrib/dataimporthandler-extras/src/java/org/apache/solr/handler/dataimport/MailEntityProcessor.java

@@ -729,7 +729,7 @@ public class MailEntityProcessor extends EntityProcessorBase {
     }
   }
 
-  class MailsSinceLastCheckFilter implements CustomFilter {
+  static class MailsSinceLastCheckFilter implements CustomFilter {
     
     private Date since;
     

solr/contrib/dataimporthandler/src/java/org/apache/solr/handler/dataimport/VariableResolver.java

@@ -167,7 +167,7 @@ public class VariableResolver {
     return TemplateUpdateProcessorFactory.getVariables(expr, cache);
   }
 
-  class CurrentLevel {
+  static class CurrentLevel {
     final Map<String,Object> map;
     final int level;
     CurrentLevel(int level, Map<String,Object> map) {

solr/contrib/dataimporthandler/src/test/org/apache/solr/handler/dataimport/AbstractDIHCacheTestCase.java

@@ -73,7 +73,7 @@ public class AbstractDIHCacheTestCase {
 
   //A limitation of this test class is that the primary key needs to be the first one in the list.
   //DIHCaches, however, can handle any field being the primary key.
-  class ControlData implements Comparable<ControlData>, Iterable<Object> {
+  static class ControlData implements Comparable<ControlData>, Iterable<Object> {
     Object[] data;
 
     ControlData(Object[] data) {

solr/contrib/dataimporthandler/src/test/org/apache/solr/handler/dataimport/AbstractSqlEntityProcessorTestCase.java

@@ -569,7 +569,7 @@ public abstract class AbstractSqlEntityProcessorTestCase extends
     return changeSet.toArray(new String[changeSet.size()]);
   }
 
-  class IntChanges {
+  static class IntChanges {
     public Integer[] changedKeys;
     public Integer[] deletedKeys;
     public Integer[] addedKeys;

solr/contrib/dataimporthandler/src/test/org/apache/solr/handler/dataimport/TestContentStreamDataSource.java

@@ -109,7 +109,7 @@ public class TestContentStreamDataSource extends AbstractDataImportHandlerTestCa
     fail("Commit should have occured but it did not");
   }
   
-  private class SolrInstance {
+  private static class SolrInstance {
     String name;
     Integer port;
     File homeDir;

solr/contrib/extraction/src/java/org/apache/solr/handler/extraction/XLSXResponseWriter.java

@@ -98,7 +98,7 @@ class XLSXWriter extends TextResponseWriter {
   SolrQueryRequest req;
   SolrQueryResponse rsp;
 
-  class SerialWriteWorkbook {
+  static class SerialWriteWorkbook {
     SXSSFWorkbook swb;
     Sheet sh;
 

solr/contrib/ltr/src/java/org/apache/solr/ltr/LTRScoringQuery.java

@@ -300,7 +300,7 @@ public class LTRScoringQuery extends Query {
     return field;
   }
 
-  public class FeatureInfo {
+  public static class FeatureInfo {
     final private String name;
     private float value;
     private boolean used;

solr/contrib/ltr/src/test/org/apache/solr/ltr/TestLTRReRankingPipeline.java

@@ -80,7 +80,7 @@ public class TestLTRReRankingPipeline extends LuceneTestCase {
     return features;
   }
 
-  private class MockModel extends LTRScoringModel {
+  private static class MockModel extends LTRScoringModel {
 
     public MockModel(String name, List<Feature> features,
         List<Normalizer> norms,

solr/contrib/velocity/src/java/org/apache/solr/response/VelocityResponseWriter.java

@@ -376,7 +376,7 @@ public class VelocityResponseWriter implements QueryResponseWriter, SolrCoreAwar
   }
 
   // see: http://svn.apache.org/repos/asf/velocity/tools/branches/2.0.x/src/main/java/org/apache/velocity/tools/generic/ResourceTool.java
-  private class SolrVelocityResourceTool extends ResourceTool {
+  private static class SolrVelocityResourceTool extends ResourceTool {
 
     private ClassLoader solrClassLoader;
 

solr/core/src/java/org/apache/solr/cloud/Overseer.java

@@ -431,7 +431,7 @@ public class Overseer implements Closeable {
 
   }
 
-  class OverseerThread extends Thread implements Closeable {
+  static class OverseerThread extends Thread implements Closeable {
 
     protected volatile boolean isClosed;
     private Closeable thread;

solr/core/src/java/org/apache/solr/cloud/OverseerTaskQueue.java

@@ -108,7 +108,7 @@ public class OverseerTaskQueue extends DistributedQueue {
   /**
    * Watcher that blocks until a WatchedEvent occurs for a znode.
    */
-  private final class LatchWatcher implements Watcher {
+  private static final class LatchWatcher implements Watcher {
 
     private final Object lock;
     private WatchedEvent event;

solr/core/src/java/org/apache/solr/cloud/ZkController.java

@@ -239,7 +239,7 @@ public class ZkController {
   }
 
   // notifies registered listeners after the ZK reconnect in the background
-  private class OnReconnectNotifyAsync implements Callable {
+  private static class OnReconnectNotifyAsync implements Callable {
 
     private final OnReconnect listener;
 

solr/core/src/java/org/apache/solr/core/CachingDirectoryFactory.java

@@ -48,7 +48,7 @@ import org.slf4j.LoggerFactory;
  * 
  */
 public abstract class CachingDirectoryFactory extends DirectoryFactory {
-  protected class CacheValue {
+  protected static class CacheValue {
     final public String path;
     final public Directory directory;
     // for debug

solr/core/src/java/org/apache/solr/handler/CdcrReplicator.java

@@ -207,7 +207,7 @@ public class CdcrReplicator implements Runnable {
   /**
    * Exception to catch update request issues with the target cluster.
    */
-  public class CdcrReplicatorException extends Exception {
+  public static class CdcrReplicatorException extends Exception {
 
     private final UpdateRequest req;
     private final UpdateResponse rsp;

solr/core/src/java/org/apache/solr/handler/CdcrReplicatorState.java

@@ -197,7 +197,7 @@ class CdcrReplicatorState {
 
   }
 
-  class BenchmarkTimer {
+  static class BenchmarkTimer {
 
     private long startTime;
     private long runTime = 0;
@@ -266,7 +266,7 @@ class CdcrReplicatorState {
 
   }
 
-  private class ErrorQueueEntry {
+  private static class ErrorQueueEntry {
 
     private ErrorType type;
     private Date timestamp;
@@ -277,7 +277,7 @@ class CdcrReplicatorState {
     }
   }
 
-  private class FixedQueue<E> extends LinkedList<E> {
+  private static class FixedQueue<E> extends LinkedList<E> {
 
     private int maxSize;
 

solr/core/src/java/org/apache/solr/handler/ExportWriter.java

@@ -939,7 +939,7 @@ public class ExportWriter implements SolrCore.RawWriter, Closeable {
     public int resetValue();
   }
 
-  class IntDesc implements IntComp {
+  static class IntDesc implements IntComp {
 
     public int resetValue() {
       return Integer.MIN_VALUE;
@@ -956,7 +956,7 @@ public class ExportWriter implements SolrCore.RawWriter, Closeable {
     }
   }
 
-  class IntAsc implements IntComp {
+  static class IntAsc implements IntComp {
 
     public int resetValue() {
       return Integer.MAX_VALUE;
@@ -1032,7 +1032,7 @@ public class ExportWriter implements SolrCore.RawWriter, Closeable {
     public long resetValue();
   }
 
-  class LongDesc implements LongComp {
+  static class LongDesc implements LongComp {
 
     public long resetValue() {
       return Long.MIN_VALUE;
@@ -1049,7 +1049,7 @@ public class ExportWriter implements SolrCore.RawWriter, Closeable {
     }
   }
 
-  class LongAsc implements LongComp {
+  static class LongAsc implements LongComp {
 
     public long resetValue() {
       return Long.MAX_VALUE;
@@ -1125,7 +1125,7 @@ public class ExportWriter implements SolrCore.RawWriter, Closeable {
     public float resetValue();
   }
 
-  public class FloatDesc implements FloatComp {
+  public static class FloatDesc implements FloatComp {
     public float resetValue() {
       return -Float.MAX_VALUE;
     }
@@ -1141,7 +1141,7 @@ public class ExportWriter implements SolrCore.RawWriter, Closeable {
     }
   }
 
-  public class FloatAsc implements FloatComp {
+  public static class FloatAsc implements FloatComp {
     public float resetValue() {
       return Float.MAX_VALUE;
     }
@@ -1219,7 +1219,7 @@ public class ExportWriter implements SolrCore.RawWriter, Closeable {
     public double resetValue();
   }
 
-  public class DoubleDesc implements DoubleComp {
+  public static class DoubleDesc implements DoubleComp {
     public double resetValue() {
       return -Double.MAX_VALUE;
     }
@@ -1235,7 +1235,7 @@ public class ExportWriter implements SolrCore.RawWriter, Closeable {
     }
   }
 
-  public class DoubleAsc implements DoubleComp {
+  public static class DoubleAsc implements DoubleComp {
     public double resetValue() {
       return Double.MAX_VALUE;
     }
@@ -1712,7 +1712,7 @@ public class ExportWriter implements SolrCore.RawWriter, Closeable {
     }
   }
 
-  public class IgnoreException extends IOException {
+  public static class IgnoreException extends IOException {
     public void printStackTrace(PrintWriter pw) {
       pw.print("Early Client Disconnect");
     }

solr/core/src/java/org/apache/solr/handler/IndexFetcher.java

@@ -1690,7 +1690,7 @@ public class IndexFetcher {
     }
   }
 
-  private class DirectoryFile implements FileInterface {
+  private static class DirectoryFile implements FileInterface {
     private final String saveAs;
     private Directory copy2Dir;
     private IndexOutput outStream;
@@ -1725,7 +1725,7 @@ public class IndexFetcher {
     }
   }
 
-  private class LocalFsFile implements FileInterface {
+  private static class LocalFsFile implements FileInterface {
     private File copy2Dir;
 
     FileChannel fileChannel;

solr/core/src/java/org/apache/solr/handler/SQLHandler.java

@@ -141,7 +141,7 @@ public class SQLHandler extends RequestHandlerBase implements SolrCoreAware, Per
   /*
    * Only necessary for SolrJ JDBC driver since metadata has to be passed back
    */
-  private class SqlHandlerStream extends JDBCStream {
+  private static class SqlHandlerStream extends JDBCStream {
     private final boolean includeMetadata;
     private boolean firstTuple = true;
     List<String> metadataFields = new ArrayList<>();

solr/core/src/java/org/apache/solr/handler/component/ExpandComponent.java

@@ -521,7 +521,7 @@ public class ExpandComponent extends SearchComponent implements PluginInfoInitia
     rb.rsp.add("expanded", expanded);
   }
 
-  private class GroupExpandCollector implements Collector, GroupCollector {
+  private static class GroupExpandCollector implements Collector, GroupCollector {
     private SortedDocValues docValues;
     private MultiDocValues.OrdinalMap ordinalMap;
     private SortedDocValues segmentValues;
@@ -614,7 +614,7 @@ public class ExpandComponent extends SearchComponent implements PluginInfoInitia
     }
   }
 
-  private class NumericGroupExpandCollector implements Collector, GroupCollector {
+  private static class NumericGroupExpandCollector implements Collector, GroupCollector {
     private NumericDocValues docValues;
 
     private String field;
@@ -763,7 +763,7 @@ public class ExpandComponent extends SearchComponent implements PluginInfoInitia
 
   // this reader alters the content of the given reader so it should not
   // delegate the caching stuff
-  private class ReaderWrapper extends FilterLeafReader {
+  private static class ReaderWrapper extends FilterLeafReader {
 
     private String field;
 

solr/core/src/java/org/apache/solr/handler/component/HttpShardHandlerFactory.java

@@ -283,7 +283,7 @@ public class HttpShardHandlerFactory extends ShardHandlerFactory implements org.
    * If all nodes prefer local-cores then a bad/heavily-loaded node will receive less requests from healthy nodes.
    * This will help prevent a distributed deadlock or timeouts in all the healthy nodes due to one bad node.
    */
-  private class IsOnPreferredHostComparator implements Comparator<Object> {
+  private static class IsOnPreferredHostComparator implements Comparator<Object> {
     final private String preferredHostAddress;
     public IsOnPreferredHostComparator(String preferredHostAddress) {
       this.preferredHostAddress = preferredHostAddress;

solr/core/src/java/org/apache/solr/handler/component/PivotFacetFieldValueCollection.java

@@ -301,7 +301,7 @@ public class PivotFacetFieldValueCollection implements Iterable<PivotFacetValue>
   }
     
   /** Sorts {@link PivotFacetValue} instances by their count */
-  public class PivotFacetCountComparator implements Comparator<PivotFacetValue> {    
+  public static class PivotFacetCountComparator implements Comparator<PivotFacetValue> {
     public int compare(PivotFacetValue left, PivotFacetValue right) {
       int countCmp = right.getCount() - left.getCount();
       return (0 != countCmp) ? countCmp : 
@@ -310,7 +310,7 @@ public class PivotFacetFieldValueCollection implements Iterable<PivotFacetValue>
   }
   
   /** Sorts {@link PivotFacetValue} instances by their value */
-  public class PivotFacetValueComparator implements Comparator<PivotFacetValue> {
+  public static class PivotFacetValueComparator implements Comparator<PivotFacetValue> {
     public int compare(PivotFacetValue left, PivotFacetValue right) {
       return compareWithNullLast(left.getValue(), right.getValue());
     }

solr/core/src/java/org/apache/solr/handler/component/TermsComponent.java

@@ -353,7 +353,7 @@ public class TermsComponent extends SearchComponent {
     return sreq;
   }
 
-  public class TermsHelper {
+  public static class TermsHelper {
     // map to store returned terms
     private HashMap<String, HashMap<String, TermsResponse.Term>> fieldmap;
     private SolrParams params;

solr/core/src/java/org/apache/solr/highlight/DefaultSolrHighlighter.java

@@ -750,7 +750,7 @@ public class DefaultSolrHighlighter extends SolrHighlighter implements PluginInf
   }
 
   // Wraps FVH to allow pass-by-reference. Public access to allow use in 3rd party subclasses
-  public class FvhContainer {
+  public static class FvhContainer {
     FastVectorHighlighter fvh;
     FieldQuery fieldQuery;
 

solr/core/src/java/org/apache/solr/schema/ManagedIndexSchema.java

@@ -368,13 +368,13 @@ public final class ManagedIndexSchema extends IndexSchema {
   }
 
 
-  public class FieldExistsException extends SolrException {
+  public static class FieldExistsException extends SolrException {
     public FieldExistsException(ErrorCode code, String msg) {
       super(code, msg);
     }
   }
 
-  public class SchemaChangedInZkException extends SolrException {
+  public static class SchemaChangedInZkException extends SolrException {
     public SchemaChangedInZkException(ErrorCode code, String msg) {
       super(code, msg);
     }

solr/core/src/java/org/apache/solr/schema/RandomSortField.java

@@ -160,7 +160,7 @@ public class RandomSortField extends FieldType {
 
 
 
-  public class RandomValueSource extends ValueSource {
+  public static class RandomValueSource extends ValueSource {
     private final String field;
 
     public RandomValueSource(String field) {

solr/core/src/java/org/apache/solr/search/ComplexPhraseQParserPlugin.java

@@ -59,9 +59,9 @@ public class ComplexPhraseQParserPlugin extends QParserPlugin {
   /**
    * Modified from {@link org.apache.solr.search.LuceneQParser} and {@link org.apache.solr.search.SurroundQParserPlugin.SurroundQParser}
    */
-  class ComplexPhraseQParser extends QParser {
+  static class ComplexPhraseQParser extends QParser {
 
-    final class SolrQueryParserDelegate extends SolrQueryParser {
+    static final class SolrQueryParserDelegate extends SolrQueryParser {
       private SolrQueryParserDelegate(QParser parser, String defaultField) {
         super(parser, defaultField);
       }

solr/core/src/java/org/apache/solr/search/ExportQParserPlugin.java

@@ -121,7 +121,7 @@ public class ExportQParserPlugin extends QParserPlugin {
     }
   }
   
-  private class ExportCollector extends TopDocsCollector  {
+  private static class ExportCollector extends TopDocsCollector  {
 
     private FixedBitSet[] sets;
 

solr/core/src/java/org/apache/solr/search/ExtendedDismaxQParser.java

@@ -956,7 +956,7 @@ public class ExtendedDismaxQParser extends QParser {
     
     /** A simple container for storing alias info
      */
-    protected class Alias {
+    protected static class Alias {
       public float tie;
       public Map<String,Float> fields;
     }
@@ -1597,7 +1597,7 @@ public class ExtendedDismaxQParser extends QParser {
   /**
    * Simple container for configuration information used when parsing queries
    */
-  public class ExtendedDismaxConfiguration {
+  public static class ExtendedDismaxConfiguration {
     
     /**
      * The field names specified by 'qf' that (most) clauses will 

solr/core/src/java/org/apache/solr/search/HashQParserPlugin.java

@@ -59,7 +59,7 @@ public class HashQParserPlugin extends QParserPlugin {
     return new HashQParser(query, localParams, params, request);
   }
 
-  private class HashQParser extends QParser {
+  private static class HashQParser extends QParser {
 
     public HashQParser(String query, SolrParams localParams, SolrParams params, SolrQueryRequest request) {
       super(query, localParams, params, request);
@@ -74,7 +74,7 @@ public class HashQParserPlugin extends QParserPlugin {
     }
   }
 
-  private class HashQuery extends ExtendedQueryBase implements PostFilter {
+  private static class HashQuery extends ExtendedQueryBase implements PostFilter {
 
     private String keysParam;
     private int workers;
@@ -135,7 +135,7 @@ public class HashQParserPlugin extends QParserPlugin {
       return searcher.rewrite(constantScoreQuery).createWeight(searcher, false, boost);
     }
 
-    public class BitsFilter extends Filter {
+    public static class BitsFilter extends Filter {
       private FixedBitSet[] bitSets;
       public BitsFilter(FixedBitSet[] bitSets) {
         this.bitSets = bitSets;
@@ -166,7 +166,7 @@ public class HashQParserPlugin extends QParserPlugin {
     }
 
 
-    class SegmentPartitioner implements Runnable {
+    static class SegmentPartitioner implements Runnable {
 
       public LeafReaderContext context;
       private int worker;
@@ -238,7 +238,7 @@ public class HashQParserPlugin extends QParserPlugin {
     }
   }
 
-  private class HashCollector extends DelegatingCollector {
+  private static class HashCollector extends DelegatingCollector {
     private int worker;
     private int workers;
     private HashKey hashKey;
@@ -271,7 +271,7 @@ public class HashQParserPlugin extends QParserPlugin {
     public long hashCode(int doc) throws IOException;
   }
 
-  private class BytesHash implements HashKey {
+  private static class BytesHash implements HashKey {
 
     private SortedDocValues values;
     private String field;
@@ -303,7 +303,7 @@ public class HashQParserPlugin extends QParserPlugin {
     }
   }
 
-  private class NumericHash implements HashKey {
+  private static class NumericHash implements HashKey {
 
     private NumericDocValues values;
     private String field;
@@ -331,7 +331,7 @@ public class HashQParserPlugin extends QParserPlugin {
     }
   }
 
-  private class ZeroHash implements HashKey {
+  private static class ZeroHash implements HashKey {
 
     public long hashCode(int doc) {
       return 0;
@@ -342,7 +342,7 @@ public class HashQParserPlugin extends QParserPlugin {
     }
   }
 
-  private class CompositeHash implements HashKey {
+  private static class CompositeHash implements HashKey {
 
     private HashKey key1;
     private HashKey key2;

solr/core/src/java/org/apache/solr/search/ReRankCollector.java

@@ -139,7 +139,7 @@ public class ReRankCollector extends TopDocsCollector {
     }
   }
 
-  public class BoostedComp implements Comparator {
+  public static class BoostedComp implements Comparator {
     IntFloatHashMap boostedMap;
 
     public BoostedComp(IntIntHashMap boostedDocs, ScoreDoc[] scoreDocs, float maxScore) {